Grinding machine rapid advance motor



May 15,' 1962 J. DECKER 3,034,265

GRINDING MACHINE RAPID ADVANCE MOTOR Filed Sept. 7, 1960 6 Sheets-Sheetl INVENTOR. JACOBDECKER TTORNEYS May 15, 1962 J. DECKER GRINDING MACHINERAPID ADVANCE MOTOR 6 Sheets-Sheet 2 Filed Sept. '7, 1960 INVENTOR.J/ICOB DECKER flTTOR/VEYS May 15, 1962 J. DECKER 3,034,265

GRINDING MACHINE RAPID ADVANCE MOTOR Filed Sept. 7, 1960 6 Sheets-Sheet5 8 INVENTOR. 84 4 JA 00B DECKER R P v /24 yWI 21 M L J HTTORNEYS May15, 1962 J. DECKER GRINDING MACHINE RAPID ADVANCE MOTOR 6 Sheets-Sheet 4Filed Sept. 7, 1960 lZZ INVENTOR. JACOB DECKER yzytk flTTOfPN EYS May15, 1962 Filed Sept. '7, 1960 J. DECKER GRINDING MACHINE RAPID ADVANCEMOTOR 6 Sheets-Sheet 6 CIR BYPASS FEED RATE 60/? VAL V155 H AZ 5 Z/9Z/9CR FAST-SLOW/NFEED /LS MOTOR RHTE 6 2272292 99 c'o/vnqcrs FOR as 0/?ca/vmcrs FOR 2L5 F i .5B

INVENTOR. JACOB DECKER United States Patent f 3 034,265 GRINDING MACHINERAND ADVANCE MOTOR Jacob Decker, Cincinnati, Ohio, assignor to TheCincinnati Milling Machine Company, Cincinnati, Ohio, a corporation ofOhio Filed Sept. 7, 1969, Ser. No. 54,440 1 Claim. (Cl. 51-165) anceafter a grinding operation is completed. The feed movement takes placeduring the cutting portion of the grind cycle. A hydraulic piston'andcylinder is generally used in the plain and angular slide types ofhydraulic grinders equipped for automatic cycle to provide axialtranslation of a crossfeed screw during the rapid movement. Thecrossfeed screw is then rotated by a feed motor to provide the feedmovement. Although this is a practical and successful mechanism forthese machines, it has not proved to be adaptable to the universal typegrinder which is distinguished in one respect from the plain and angularslide machines by its wheelhead which is mounted on a swivel base toallow for angular adjustment of the cutting surface of the wheelrelative to the axis of a workpiece. It is desirable to provide anautomatic cycle for the universal grinder, however, even though seriouslimitations are imposed on the infeed mechanism of such an automaticuniversal grinder. The mechanisms must not interfere with the swivelmounting of the wheelhead and should not substantially add to the shopspace required for operation of the machine. Therefore, conventional useof the crossfeed screw is inconvenient since it limits the swivelmovement of the wheelhead. The hydraulic piston and cylinder adds--bulky structure to the rear of the machine and becomes impractical asa means for furnishing rapid translation of the feed mechanism.

It is therefore an object of this invention to furnish an infeedmechanism which does not interfere with the swivel mounting of auniversal grinder wheelhead.

It is a further object to supply an infeed mechanism for an automaticcycle machine which can be contained within the base of the machine withno resulting increase in bulk of the machine which would causeadditional shop space requirements. I

Other objects and advantages of the present invention should be readilyapparent by reference to the following specification, considered inconjunction with the accompanying drawings forming a part thereof, andit it to be understood that any modifications may be made in the exactstructural details there shown and described, within the scope of theappended claim, without depart ing from or exceeding the spirit of theinvention.

When constructed in accordance with the preferred form of thisinvention, a grinder infeed mechanism utilizes a rack and pinion drive,the rack being fixed to the wheelhead and the pinion being fixed on arotatable drive shaft supported in the machine base on which thewheelhead is received. This rack and pinion arrangement provides boththe rapid movement of the wheelhead toward and away from the workpieceand also the slower feed movement. The pinion is connected to the feedmotor by a driving train which includes, between the feed motor and thepinion, a rapid advance motor so that the pinion can be driven either byoperation of the rapid advance motor or by operation of the feed motorthrough the rapid advance motor. The drive shaft rotates around a fixedaxis and by placing the axis about which the wheelhead is made to swivelon this same axis, the engagement between the drive shaft and thewheelhead can be maintained for any angular position of the wheelhead.The rapid rotation of the drive shaft producing rapid movement of thewheelhead is provided by a paddle type motor. The body of the motor iscarried on the drive shaft. The drive shaft extends into the motor bodywhere a paddle extending from the shaft is received for limited rotarymovement. The motor body is easily contained within the base of themachine where the drive shaft is supported. When the paddle is rotatedto produce rapid movement, this motor body is in a fixed positionrelative to the base, but during feed movement it rotates with thedrive' shaft. The feed power is furnished by a separate feed motorduring feed but which is utilized as a brake mechanism to restrainrotationof the body of the paddle motor when that motor is operated.

A clear understanding of the construction and operation of thisinvention may be obtained from the fol-lowing detailed description andthe attached drawings wheretions broken away for clarity.

FIG. 2 is a sectional view of the infeed mechanism of the grinder inFIG. 1 on line 2-2.

FIG. 3 is a section of FIG, 2 on line 33.

FIG. 4A and FIG. 4B show the hydraulic feed circuit of the machine.

FIG. 5A and FIG. 5B show the electrical control cirbase 13 of themachine and is pivotally adjustable thereon. The exposed portion of FIG.1 shows the location of the feed mechanism which is contained in thebase 18 by the motor enclosure portion 20 of the base. The cross feedshaft 22 extends through the motor enclosure portion to the front of themachine where it is geared to a handwheel assembly 106 (FIG. 4B) and thehydraulic feed motor 118, located at the front of the machine below thetable.

The section view in FIG. 2 shows the structural details of the paddlemotor. The wheelhead 10 which carries a grinding wheel 24 and guard 26,is located on the ways 14- in the intermediate member 12. Theintermediate member is located on the top of base 18 and is pivotallyadjustable on the swivel surface 28. Y A rack 30 is fixed to thewheelhead .10 and extends parallel to the ways 14. The rack is engagedby split pinion 32. The lower part 32a of the split pinion is fixed to adrive shaft 34 and the upper part 3% is fixed to a torsion bar 36. Thetorsion bar is received through the drive shaft 34 and has securedthereto a clamp 38 held against rotation relative to drive shaft 34 bypins (not shown). The torsion bar and drive shaft 3-4 have a relativetwist which is preserved by the split pinion being engaged with the rackon one end and the clamp 38 on the other end. This twist eliminatesbacklash between the rack and pinion. The dfive shaft is supported inthe motor enclosure portion 20 of the base 18 in tapered annularbearings 40 and 42. The housing or body of the paddlemotor 43 iscomprised of a top member 44, a middle member 46, and a lower member 48on which a worm wheel form has been machined. The body is received onthe shaft 34 and held Patented May 15, 1962 in place by nuts 59 and 52.The drive shaft 34 is rotat- ,able in limited amount relative to thebody in annular bearings 54 and'56. These bearings 54 and 56 also holdthe shaft and body rigidly concentric relative to each other. The wormwheel form of the lower portion 48 of the motor body is engagedby a worm58 which is fixed on the'cr'ossfeed shaft 22.

FIG. 3. shows a cross section of the paddle motor received on the driveshaft 34. The motor body encompasses a cavity 62 which'is concentricwith the shaft 34 and has a radial wall member fid'fixe'd'therein. Thiswall, which is connectedto memberdti limits the cavity 62 man angulararcrof less than 360 degrees around the shaft. Extending from the shaftis the paddle segment 65 which is fixed to theshaft and received in thecavity The paddle segment may be swung within the limits of the cavity52 from oneside of the wall 64 to the other to produce the limitedrotary movement ofthe shaft 3'4 relative-to the body of themotor 43;Positive stops 68 are "fixed in each side of the wall 64 to engage stoppa ds' .70 of the paddle segment 66 as that segmentis caused to movefrorrron'e end of the arcuatecavity to the other end.

to fluid passage 76 (FIG. 2). That line opens through port 72 (FIG. 3)tothe c'avity in the paddle motoron one side of the paddle segment 66which swings to rotate shaft '34. Atthe same time, fluid line 90 whichconnects to fluid passage 73 (FIG. 2-) opening through port 74 (FIG. 3)to thecavity on the other side of the paddle I segment and line 92 (PEG.4A) are connected through motion mechanism in the driving train betweenthe feed motor 118 and the wheelhead 10 to produce a fixed amount ofrapid movement of the wheelhead. When the peddlesegment completes itsswing, the rapid advance movement is stopped, and the pressure switch3P3 (FIG.

, 4A) is operated. Pressure continues to be supplied to the Fluid underpressure is selectively supplied 'to the cavity:

through ports 72 and 74 in th'e shaft 34, which are terminal cndsoffluid lines 76 and '78 (FIG; 2') and the ports 64:: (the port includingan adjustable ball restriction in the wall member 64). Lines 76 and 78are'selectively connectable to a source of fluid under pressure and to{drain to supply fluid under pressure to the cavity d2 between thepaddle segment 66 and one side of the wall member 6-4- and to removefluid from the cavity between the paddle segment and the other side ofthe wall member. This causes the paddle-segment to swing within thecavity from engagement with one side of the wall member 64 to'engagementwiththe other side. In swinging,

the paddle segment rotates the drive shaft 34 to which it is fixed.

FIG. 4A and FIG. 4B show the hydraulic circuit of and relief valve RVare assumed to bei-in operation-as are all of'the electrical elements ofthe machine. To

paddle motor through line .92 however. I This holds the paddle segmentagainst the wall in the rnotor housing and the paddle motor becomes arigid part of the driving train. 7 V

When pressure switch SP8 is operated solenoid ZSOL is energized andthe'plunger of the pilot valve 126 is caused toshift left and pressurefrom line 84 is applied the grinding machine described. The hydraulicpump P T initiate the cyc1e,.a lever-8ilf(FlG. 4B) of the cycle. 7

start valve EZ/is pulled forward and the full pressure line' 84 isconnected to a hydraulic line 86 connected to-the pressure'switch 5P8.Conversely, pushing lever 80in the opposite direction connects pressureline 84 to'line 85.

This will operate pressure switch 4P8 and terminate automatic cycling.Upon the operation of the pressure switch 5P8, solenoid ISOL (FIG. 4A)is energized to shift the plunger of valve 94- down; Fluid lines 34 and88 are connected and lines 90 and 92 are connected in the Wheelheadcontrol valve 94. Line 92 connects through valve 168 to the drain line124. Pressureis connected through the selector valve .96 (FIG. 4A) fromline 88 to line 98 nected through valve 96 (FIG. 4A) to line 9% which isnow connected to the main return line 92. The fluid is Z and the shifterbracket 100 (FIG. 4B). Line 174 is conallowed to escape from the rightside of the shifter 10% (1 16.413). The shifter .moves to the right andmeshes gear 192 with gear 194 in the handwheel mechanism 1%. Gear 104 ismounted to rotate gear 108 which in turn is meshed with gear lltl on theend of the crossfeed shaft Worm gear 116., The worm gear 116 is drivenby'the hydraulic feed motor 1-18 through gears 12%: and 12,2. As long asthehydraulic feed motor .is maintained in a static condition the paddlemotor body of the paddle motor 43 (FIG. '2) will not be allowed to turnsince the described gear traiirand hydraulic feed motor are allmechanically connected and furnish a braking mechanism to opposerotation of the paddle motor body. When switch SP8 is closed,fluid-under pressure is also supplied from line 84 through'valve 94 toline 88 which connects r to line 128; I The plunger of the motor cut-offvalve 130 shifts right when pressure is in line 1 28. Line 132 isconnected .to line 134. At the same time, the plunger of. the pilotvalve 136 has shifted left since solenoid 4SOL is also energized whenpressure switch 3P8 is operated and pressure from. line 84 is connectedto line 138 to shift a the plunger of the fast rate cut-off valve 144}to the right. I

At this time lines -88 and 144 are connected in the pressure reducingvalve 142. Fluid under pressure, moves through the pressure reducingvalve 142 to line1 144. From there,-the reduced pressure fluid goesthroughthe check valve -1{i6; line 134, valve 139, line 132 to themotor' reversing valve 148. where it connects to line 150;

Line 159'connects with the hydraulic feed motor "118 the crossfeed shaft22'and the worm. 58 (FIG. 2) to effect rotation of the paddle motor*body 48 and the drive shaft 34 to produce a feed movement of thewheelhead on the ways toward the table 16 (FIG. 1). Fluid is exhaustedfrom the feed motor 1 1% (FIG. 4B) by way of fluid line 1 52 whichconnects with line 154 in the motor reversing valve 148 (FIG. 4A). Line154 carries the fluid to the fast rate cut-olf valve the plunger ofwhich has shifted to the right to connect lines 15 and 156. A The returnfluid from. the feed-motor passes through the fast grind rate valve 158to the returnline IMdraining tQ the fluid reservoir. The setting of thefast grind rate valve then controls the Wheelhead feed rate for thefirst period of the grinding cycle. 5 V

After apredetermined amount of feed movement, so-

amount of feed at this slower rate, the feed is stopped completely by apositive stop (not shown) engaged by the handwheel mechanism 106. Aftera predetermined time, solenoid ISOL is deenergized and the plunger ofthe wheelhead control valve 94 is caused to shift back to the positionshown. Lines 84 and 90 are connected and lines 88and 92 are connected.This reverses thefiuid pressure differential in the paddle motor 43 andthepaddle segment swings rapidly back to its initial position.

The rotation of the drive shaft 34 (FIG. 2) is reversed and thewheelhead rapidly retracts from the workpiece, the amount of retractionbeing equal but opposite to the rapid advance movement. The feed motor118 (FIG. 4B) and the gear train connecting to the paddle motor bodyagain act as a brake to restrain the movement of the paddle motor bodyrelative to the machine base. At

-the end of the rapid retraction, the fluid pressure diiferential in thepaddle motor holds the motor body and drive shaft in a relatively fixedrelationship.

When the plunger of the wheelhead control valve Q4 changes its positionto connect lines 88 and 92, and lines 84 and 9!}, pressure through line90, the crossfeed selector valve 96, and line 174 attempts to move theshifter bracket 100 (FIG. 4B) to the left, tending to engage gears 164and 110 to reverse rotation of the crossfeed shaft 22. At the same time,the pressure in line 90 is causing the plunger in the reversing valve148 (FIG. 4A) to move upward to the position shown at a rate controlledby the restriction 166. During the shift, lines 132 and 152. and lines150 and 154 are momentarily connected. This provides a momentaryreversal of the feed motor 118 allowing the backlash between the gears164 and 110- to,be adjusted to allow these gears to mesh. Lines 132 and150 and lines 154 and 152 are reconnected then and the fluid motor 118again runs in the original direction. Solenoid SSOL is energized at thesame time that the rapid retraction takes place and the plunger of valve171 shifts to the left to connect pressure line 84 to line 170. Whenpressure is in line 170, the plunger of valve 168 shifts left. Line 154is connected to drain line 124. The feed motor 118 runs at a rapid ratenow to restore the wheelhead to its starting position. Since at thestart of the retraction stroke, the feed motor and rapid retractionmotor may be both operating at the same time for a brief period, theworm wheel 114 (FIG. 4B) driven by the feed motor 118 is furnished withan over-running clutch (not shown) to prevent the rapid retractionmovement of the paddle motor from turning the hydraulic feed motor andcausing interference with the normal motor action when the rapidretraction takes place. 7

The hydraulic feed motor runs until the wheelhead has reached itsinitial position relative to the work table and solenoids ZSOL and SSOLare deenergized. The plunger of the motor cut-off valve is caused tomove left and to block line 134 from line' 132. The plunger of the ratevalve by-pass valve 168 moves to the right to block line 154 from thereturn line 124 and the hydraulic system is returned to its initialstatic condition ready for another cycle.

r The electrical control circuit for the wheelhead mechanism describedis shown in FIGS. 5A and 5B. (Horizontal reference locations on FIGS. 5Aand 53 will be indicated as a number prefixed with the letter Z andparenthesized herein.) To start the machine, the master start switch SW1(FIG. 5A,. Z20) is momentarily closed to connect relay 3M (Z20) acrossthe control voltage lines LL1 and LL2 through closed contacts of thestop switch SW2 and contacts of switch SW1. Relay 3M is energized andpicks up. The hydraulic pump motor MTRS (Z6) is then energized throughcontacts of the relay 3M which connect the motor MTR3 to power supplylines L1, L2, L3. When the hydraulic pressure produced by the pump P(FIG. 4A) which is driven by motor MTR3 reaches a preset level, thepressure switch 1P8 is operated and its contacts (FIG. 5A, Z23) areclosed. Switch SW1 may be momentarily closed again to pick up thegrinding wheel motor start relay 1M (Z23). When relay 1M is picked up,the grinding wheel motor MTR1 (Z3) is connected to power lines L1, L2,L3 through contacts of the relay 1M.

After the machine electrical circuits are energized and before thegrinding cycle is commenced, a dog 130' (FIG. 4B) on the gearing of theinternal portion106a of the handwheel mechanism 196 operates the limitswitch 1LS.

(The handwheel mechanism is geared to the feed motor such that theinternal portion 106a rotates relative to the linkages 132, 184 as the.feed motor 118 is operated. Also, with selector valve 96 (FIG. 4A) inthe position shown, line 172 is not pressurized and the plunger 186 isforced down by the lever. 188 and spring 190 to allow limit SWitChlLS tobe operated by the handwheel mechanism 196a; During setup, line 172 isconnected to pressure linedd-through selector valve 96 to elevateplunger 1'86 and hold the limit switches 1LS and 2L5 in their lowerpositionas shown against an elevating bias force. in this conditionlimit switch 1LS operated and limit switch 2LS unoperated which puts thecontrol circuit in a condi tion suitable for manual operation.) RelayGCR (FIG. SB, Z38) is picked up at the start of the cycle throughcontacts of the limit switch 1L3. The cycle start switch SW3 (FIG. 5B,Z25) may be closed now to start the grinding machine through a cycle ofoperation. When switch SW3 is momentarily closed, relay 10R (Z25) ismomentarily picked up through contacts of the pressure switch 4P8, cyclestop switch SW4 and switch SW3. (By pulling the lever an (FIG. 4B)forward, contacts of pressure switch SPS (FIG. 5B, Z26) are momentarilyclosed and will start the cycle as previously described by furnishing aby-pass circuit aroundthe switch SW3.) When relay ICR is up, the relays2CR1 (Z27) and 2CR2 (Z28) are picked up through contacts of relays lCR,6CR, switch 4P8 and the switch SW4. Relays 2CR1 and ZCRZ latch upthrough contacts of relay 2CR1 and the tarry timer 2TR (normally closed,time opened, instantaneous closed). When relay 2CR1 is up, solenoid 1SOL(Z16) is energized and shifts the wheel-head control valve 94 (FIG. 4A)plunger to start the rapid infeed movement of the wheelhead. Therelay2CR2 being up causes the motor control relay 5M to be picked up, Whenthe relay 5M is up, the headstock motor MTRS (Z9) is connected to linesL1, L2, L3 through contacts of relay 5M. Motor MTRS rotates theworkpiece during the grinding operation. Relay 2CR2 being up also causesrelay 50R (Z37) to be picked up through contacts of relays 2CR2 and 7CR(normally closed) and solenoid 4SOL (Z19) is energized through contactsof relay SCR. This shifts the pilot valve 136 (FIG. 4A) left and a fluidreturn path is opened through the fast feed rate valve 158 from the feedmotor 118 (FIG. 48).

At the end of rapid advance, pressure switch SPS is operated and relaySCR (FIG. 5B, Z29) is picked up through contacts of relays 7CR (normallyclosed) and 2CR2 and the pressure switch 3P8. Solenoid ZSOL (FIG. 5A.,Z17) is energized through contacts of relay 3CR. The pilot valve 126(FIG. 4A) shifts left and causes the motor cut-off valve to allow fluidto flow through the hydraulic feed motor 118 (FIG. 4B). The feedingmovement of the wheelhead begins. As the feeding movement begins, thehandwheel mechanism 106 begins to rotate and theldog 18!) moves to aposition to allow limit switch 1L8 to be released. The contacts of limitswitch 1L8 (FIG. 53, Z38) are opened and relay 6CR (Z38) is dropped.After apredetermined amount of feed movement, the limit switch 2L8 (FIG.4B) is op erated as the roller 192 on the internal portion 196a of thehandwheel mechanism 196 has been rotated to a position allowing thelever 184 to move up. The control relay 7CR (FIG. 5B, Z39) is picked upthrough contacts of limit switch ZLS. When relay 7CR picks up, relay SGR(Z37) is dropped and solenoid 4SOL (Z19) is deenergized. The fast feedrate cut-off valve (FIG. 4A) sends the return fluid from the feed motor118 through the slow feedrate valve 162. The spark out timer 2TR (FIG.5B,, Z34) is started when relay 7CR is pickedup and the contacts thereofin the timer circuit are closed. During the time that the timer 2TR isoperating, the handwheel mechanism engages the positive stop (not shown)and further feed movement of the wheelhead is prevented. Shortlythereafter, the timer The infeed motor ,is not stopped when relay21313-2 is dropped since a latch'circiiitexists through the-nort mallyclosed contacts of reIaysZCRZ md fiCR andfco'ntacts of relay 30R whichholds relay ;;3 CR ener gized after the wheelheadh'as; startedretractionniove- 'At this time, after relays ,Z CRl and 2CR2 merit. havedropped, the'plunger of the reversing valve 148 '(FIG. 4A) is shiftingand momentarily eifects reversal of the feed motor 118 (FIG. 4B) toallow the gears 164 and 11% tomesh as the'shiiter 104) moves to theleft; RelaydCR (FIG. 53, Z32) also picks up through contacts of relays3CR and ZCR i (normally closed) when relay ZCRI is dropped. When relay4CR V is picked up, solenoid 3SGL (FIG. 5A, Z18) is energized throughcontacts of relay 4CR and the feed motor exhaust fluid'is returned tothe reservoir through the byepass valve 168 (FIG. 4A). Thefeed motor 118now drives the handw'he'el 106 and the worm gear '58 in the oppositedirectionto retnrnthe handwh'eel and wheelhead to their startingpositions; During the return to the starting position, the internalportion 1960 of the handwheel release limit switch ZLS. When thewheelhead and handwhe'el have returned to their starting positions,limit switch 1L5 is operated by the internal portion 196a of thehandwheel mechanism 1%. The contacts of limit switch 1L5 (FIG. S B, Z38)are closed and relay 6CR is picked up. When relay @CR is picked up,relay 3CR (Z2?) is dropped and solenoid ZSOL (Z17) and relay 4CR (Z32)are deenergiz'ed. 1 When relay 4CR is deenergized, solenoid 3SOL (Z18)is'deenergi'zed. The electrical system and hydraulic system'are' now intheir starting condition and the cycle maybe begun again.

What is claimed is: H In a'g'rinding'machine having a source of fluidunder pressure, a base, a wheelhead, and an intermediate member mountedon the base and gpivotally adjustable thereon around an axis, saidintermediate member having a way to siidably receive. the wheelhead, amechanism to effect rapid'and feed movements of said wheelhead on saidway comprising in combination, a rack fixed on said Wheelhead andparallel to said Way, a drive shaft supported in the base for rotationon said axis, said drive shaft having a radial paddle segment extendingtherefrom and a bore therethrough," a torsion shaft, received in saidbore and extending thereth r'ough concentric with said axis, a splitpinion engaged with said rack having one portion fixed on said torsionshaft and another portion fixed on 7 said drive shaft, means to maintaina predetermined relative twist between said drive shaft and torsionshaft operable to eliminate backlash between said rack and split pinion,a motor 'body received on said drive shaft and rotatable relativethereto having a worm wheel portion and a cavity therein concentric withsaid shaft, said cavity receiving said paddle segment and having aradial wall defining extreme angular positions of the paddle 7 segmenttherein, saidcavity havinga port on each side of said wall, a shaftjournaled in the base having a worm engaged with said worm wheel portionoperable to control rotation of'said motor body relative to said base,

means selectively to connect said source of fluid'nnder pressnr'e'to oneofsaid cavity ports to swing said paddle segment to one of said extremeangular positions and rotate said drive shaft for rapid movement ofsaid-Wheelhead on said Way, a feed motor connected to said Worm shaft torotate said worm for rotation of said motor body and drive shaft toeffect a feed movement of said wheelhead on said 'Way after said paddlesegment engages said wall, the paddle segment being held against saidwall by said fluid under pressure at said one port, and meansalternately to connect said other cavity port to pressure and to reversesaid worm to retract the wheelh'ead.

References Cited in the file 0t this patent UNITED STATES PATENTSGermany 1 May 28, 1937

